The production of hollow fiber MAbs utilizes a Fiber Cell System module and a specialized pump to force liquid media through a bundle of semi-permeable fibers. Highly concentrated MAB is retained in the chamber and is utilized directly from the fiber or processed further depending on the needs of the investigator. Special protein free media is used if the MAB is to be used directly in animals. Antibodies produced by standard tissue culture techniques utilize plastic flasks and standard media. During the current fiscal year, four MAbs have been grown.